Boiler



Feb. V2, 1932. w. R. sTocKwELL 1,843,180

BOILER Filed March 17, 1928 3 Sheets-Sheet l Feb.y 2, 1932. w. R. s'rocKwELL BILER Filed March 17, 1928 5 Sheets-sheet 2.

Feb. 2, 1932.

w. R. sToiKwELL BOILER Filed March 17. 1928 3 Sheets-Sheet 3 MM5/M Patented Feb. 2, 1932 UNITED STATES PATENT OFFICE WILLIAM y2R. STOCKWELL, OF MICHIGAN CITY, INDIANA, ASSIGNOR TO WEIL-MCLAIN COMPANY, OF MICHIGAN CITY, INDIANA, A CORPORATION OF DELAWARE BOILER Application led March 17, 1928.

rIhis invention relates to improvements in boilers. n

`One of the greatest difficulties encountered in striving for efficient fuel consumption in boilers, particularly boilers of the square sectional horizontal grate smokeless type, is that of maintaining uniformity of combustion over the entire gratearea, i. e., maintenance of uniformity ofthe volume of air passing through the grate at all portions. In most boilers of the type indicated, the draft pull is at the rear end of the boiler, with a corresponding tendency to accelerate Vthe air flow through, and hence the rate of combustion of, 'the fuel over those grate bars nearest the back of the boiler. -This diculty is further likely to be increased in so-called smokeless types of boilers which generally provide for Y an auxiliary supply of air near the rear of the boiler in order to promote vsecondary combustion. v

In said square sectional types of boilers, wherein the vertical sections are arranged transversely, it is the common practice to so l proportion the sections and the supporting ase or franiethat the end portions of the sections project beyond or overhang the side walls of the base or supporting frame, lthis arrangement permitting of smaller and oo nsequently less expensive bases for a given size boiler section. Frequently it also happens that'the number of sections'placed one behind the other may vary in their total overall length from front to rear of the boiler so as to cause the rearmost section to partially Aoverhang or project beyond the back wall of the-base.

It is also well known to those skilled in the art that it is becoming increasingly impor- Aai tant commercially and economically to provide insulation 'for boilers in order to minimize radiation losses and also to increase the aesthetic appeal of the boiler, the latter result being accomplished by providing metal sheathing which maybe artistically i'inished in various colors with baked enamels and the like. A

One object of my invention is to make use of the factors of overhanging sections and the desirability of sheathing the boiler, above seriai No. 262,532.

referred to, in providing an efficientsmokeless type of boiler with uniform rate of air flow over the entire grate area, this being accomplished at a minimum amount of additional cost over that of the boilers as now commonly made.

Another object of my invention is to provide an improved arrangement for an auxiliary air supply for the grate in such manner that uniformity of air How through the fuel bed and uniformity of combustion of the fuel is obtained.

A specific object of my invention is to provide an auxiliary air supply channel directly beneath the overhanging portions of thev sections of a square section boiler whereby to minimize the space required for the boiler and at the saine time avoid the necessity of any changes in the sections, themselves.

Other objects of the invention' will more clearly appear from the description and claims hereinafter following.

In the drawings forming a part of this specification, Fig. l is a side elevation lof a square sectional type boiler having my improvements incorporated therein, a portion near the base being broken away to illustrate certain features of the improvements. Fig. 2 is a rear end elevation of the boiler shown in Fig. l. Fig. 3 is a vertical transverse sectional view corresponding to the line 3 3 of Fig. l, but upon a somewhat larger scale. Fig. 4 is a horizontal sectional view corresponding to the section line 4-4 of Fig. 3. And Figs. 5, 6A and 7 are views corresponding respectively to Figs. l, 2 and 4, but illustrating another embodiment of the invention.

Referring first to the construction illustrated in Figs. Ito 4, inclusive, the boiler is shown of that type comprising a plurality of water sections A, one of which is shown in elevation in Fig. 8. Said sections, which aie arranged transversely and placed one behind the other from front to rear of the boiler, are supported on a base which comprises side walls 10-10 and end walls 11 and 12, the base defining a rectangular ash pit below the horizontal grate, indicated at 13. The ash pit door is indicated at 14, the fuel feed door at chimney. In Figs. 1 and 2 I have indicated.V

conventionally a bellows type governor 24 Which actua-tes a lever-.25, the latter having a'chain 26 running to aI bar 27 which in turn is connected to and adapted to operate simulv taneously two doors 28-28. The chain 26 is also connected to alever 29 which in turn has a chain connection30 to a check door 31.v

Referring more particularly to Figs. 3 and 4, it will be noted that the lower ends 32 'of the legs of the sections A are supported on the side -wallslO of the base and project outwardly beyond or overhang said walls 10,` as clearly shown in Fig.` 3. I have shown the boiler sections covered with suitable heat-insulating material 33 which may be air cell asbestos and Y the layer of insulation in turn covered by a metal sheathing 34. The several sections will be, water-connected inthe usual mannerby nipples,gthe nipple openings being indicated Y at 355-36. c

. In the preferred embodiment ofthe invention, I employ secondaryk or auxiliary 'walls 37-37 which extend `lengthwise of the boiler` and.. arel outwardly spaced from the` corresponding side walls 10 of thel base,as shown in Fig. 3. :Fach of ysaid walls 37 may be in the form of a thin or light casting having an inturned bottom flange 38 resting on the floor and provided lalso preferably with yan inturned flange or shelf 39 near the top thereof, said flange `39 extending partially under the overhanging portions of the water sections.l The main web of the wall 37 is extended as indicated at 37', so as to partially, overlap the lowermost portions of the section legs andv thus leave a space within which is accommodated and held the lower edge portions of the sheathing 34. In this manner, an efcient binder forthe loweredgeportions of .thesheathing is obtained and a finished appearance given to the boiler.

From the preceding description, it will be seen thatI have providedtwo longitudinally extending air passages 40-49, one on `veach side of the boiler, each lpassage being defined by a side wall 10 of the base,'the secondary wall member 37 and the overhanging, portions-of thewater sections, the latter being abutted'one behind the other Aand thereby forming a closed top wallfor the airpassages. Said air passages 4() are closed at their front ends'by the end portions ofthe front jwall 11 of the base, as shown in Fig. 4

andthe same result'is accomplished at the rear of the boiler by the extended ends of the rear wall 12. The latter, however, has the openings 41-41 through which the supply of air is admitted to the passages 40, said openings 41 being controlled by the pivoted doors 28 which in turn are. automatically controlled through the governor 24.

As indicated in apreceding part of the defA scription, the tendency injboilersof thek type disclosed where the draft pull isat the rear, is to produce accelerated combustion near the rear of the horizontal grate and in supplying theauxiliary air Vforsmokeless combustion with my improvements, I counteract or balance the air draft by V:providing graduated series of communicating openings 42, 43, 44 and 45 in Yeach of the base side walls 10, the largest opening being near the front of the boiler and the size of said openings gradually decreasing toward the rear, as clearly indicated in Figs. 1 and 4. In this manner, as the auxiliaryv supply ofl air is admitted through the door openings 41 of the rear of theboiler, the greater draft pull normally exerted near the Arear, and which would; be effective through the smallest openings 45, is counterbalanced or neutralized bythe fact that the rlarger openings 42`farthest from the admission door, openings 41, permit the air to Vpass through easier and` in greaterrvolume, although at a lesser rate. Thus air is supplied uniformly to the entire undersideof the horizontal grate anda uniform rate of combustion obtained. v' p Y l V From the preceding description, taken in connection with the drawings, itrwill beV observed that vI utilize the space heretofore commonly wasted, i. e., the space normally left beneath the overhanging projections of the water 'sections Further, a completely encased finished appearance is given to theV boiler by the secondary wall members 37 which continue, in effect, the vertical .sides of the boiler having the smooth appearance Vprovided by the sheathing 34. As .understoodv by those skilled lthe art, the sheath-` ing 34 may be finished in any suitablemanner toincrease the aesthetic appearance of the finished boiler.Y y

' Referring to the modification illustrated in Figs. 5, Sand 7, the arrangement of water sections, base, damper controlsand the like is the same. Y In this modification, however, the modification has been adapted to those conditions where the rearmost Water section B of the boiler proj ectsbeyond oroverhangs the rear wall 112 of the base, which frequently happens. v Under such conditions, I preferably provide ak common air passage 140 along therear end of the boiler, as best shown in Fig. 7, this being provided by an end auxiliary wall 237 which, with the auxiliary side walls 137-137, completes the two side air passages 1407140. Also, in this modification, it is only necessary to employ one door 128 to govern the admission of air to the auxiliary air passages, it beingl understood that said door 128 is automatically controlled, as in the case of the doors 28, previously described. Referring to Fig. 7 it will be observed that the air coming through the door opening 141 will divide, part going to the right and part to the left and thus supplying both air passages 140, whence the auxiliary air is admitted to the ash pit spacethrough the graduated series of openings 142, 143,

144 and 145. f

In the modifications of Figs. 5, Gand 7, instead of providing separate castings to constitute the secondary walls 137 and 237, I preferably make the latter integral extensions of the boiler sheathing 134, i. e., the sheathing, both on the sides and rear end of the boiler, is carried down to the floor line, as shown. rIhis arrangementv is somewhat cheaper than that disclosed in the first modification, and may be utilized when desired.

I have herein shown and described what I now consider the preferred manner of carrying out myinvention, but the same is merely illustrative and I contemplate all changes and modifications that come within the scope of the claims appended hereto.

1. Aboiler comprising: a base; a plurality of sections supported on said base, the bottoms of said sections projecting laterally be- 1 with a base; of a plurality of sections mounted on said base and having the lowermost portions thereof projecting laterally beyond a wall of the base; an independent spaced wall member extending downwardly from the overhanging portions of the sections and spaced from the corresponding wall of the base whereby to provide a closed air passage defined by the base wall, the lspaced wall member and said overhanging portions of the sections, the wall of the base having a graduated series of openings therein.

8. In a boiler of the character described,

the combination with a rectangular base; of a plurality of transverse water sections supported on said base and havin the lower extremities of the sides thereo projecting laterally beyond the side walls of the base, said sections having flues so arranged as to create the draft pull at the rear of the boiler; separate,secondary wall members extending lengthwise of the sides of the base and, with the latter and the overhanging projections of the sections, defining air passages closed along the tops by said overhanging projections, the side walls of the base having openings therein decreasingly graduated from front to rear; and a door controlling the admission of air to said passages.

4. In a boiler, the combination with a base having front, side and rear walls; of a plurality of transverse water sections supported on said base and having the lowermost portions of the sides thereof projecting laterally beyond the side walls of the base and the rearmost section projecting rearwardly beyond the rear wall of the base; secondary, separate wall members paralleling the side and rear end walls of the base and engaging the corresponding overhanging portions of said seotions to thereby dene side air passages and a transverse rear air passage communicating with the side passages; means for admitting an auxiliary supply of air to said rear transverserair passage; and means for admitting air through the side walls of said base to the interior thereof.

5. In a boiler, the combination with a plurality of assembled transverse water sections, the bottoms of which define a rectangle; of a supporting base for said assembled sections, said base being of rectangular form and of lesser width than the width of said rectangle formed by the bottoms of the sections, whereby the sections are supported by said base at points inwardly of each side of the assembled sections to thereby leave overhanging portions; secondary wall members, separate from the base, paralleling the sides of said base and disposed substantially vertically in line with the sides of the overhanging portions of the sections whereby to form therewith and the base, side air passages, the side walls of the base being apertured to provide communication between said passages and the interior of the base; and means for admitting an auxiliary supply of air to said side air passages.

In witness that I claim the foregoing I have hereunto subscribed my name this 8th day of March 1928.

WILLIAM R. STOGKWELL. 

